Diltiazem slow-release and left ventricular hypertrophy: a volumetric approach of left ventricular mass using magnetic resonance imaging

Abstract

Aims: This study was designed to assess the changes in left ventricular mass (LVM) in hypertensive patients with left ventricular hypertrophy under drug therapy with once-daily slow-release diltiazem. Magnetic resonance imaging (MRI) was used for this purpose because of its higher reproducibility than M-mode or two- dimensional echocardiography. Methods: Patients suffering from essential hypertension were included if their baseline LVM index (LVMI) was ⩾105g/m² in male or ⩾85 g/m² in female patients, ie, equal or higher to the median values observed in hypertensive patients in our institution. MRI consisted in a true short-axis, electrocardiogram (ECG) gated spin-echo slice acquisition at baseline, after 3 and 6 months of therapy (M₀, M₃, and M₆). Data were stored on magnetic tapes and read subsequently under blind conditions and the control of an external auditor. Results: Thirty-five patients were included. Of these, 14 patients (40%) were not previously treated. Inter- and intra-observer variability for LVMI measurement were 5.6 ± 4.3% and 2.1 ± 3.0%, respectively. Mean baseline LVMI was 110 ± 16 g/m² in male and 96 ± 16 g/m² in female patients. It decreased by 3.6% at M₃ (P = 0.05) and by 6.0% at M₆ (P = 0.02). A trend towards a greater LVMI reduction was observed in previously untreated patients. Conclusion: This study confirms that MRI is a reproducible technique for the measurement of LVM. It demonstrates a significant reduction in LVMI as early as the 3rd month of therapy in hypertensive patients treated with once-daily sustained release (SR) diltiazem, although baseline LVMI in the majority of participating patients was only moderately increased.